The composition of gasoline electrical control system
There are many types and models of modern automotive gasoline electrical control systems, but the structure and principle are similar. They are also divided into sensors (sensors), electronic controllers (ECUs) and actuators (Actuator) in the same way as the electronic control of diesel fuel supply systems. three parts.
Various sensors and switches, which can transmit the driver's intention, gasoline engine working condition and environmental information to the electric controller in time and in real time. The electric controller uses other switching signals according to the input signals from the various sensors, and uses the control software. Combine the stored calibration data with the chart for analysis and calculation, determine how to control, and issue various control commands to the respective actuators with corresponding electrical signals, and the actuators generate corresponding actions to achieve the required control.
Of all sensor inputs, engine speed and air flow (or intake manifold absolute pressure) representing the engine load are the two most basic inputs. The electric controller determines the basic values of the ignition advance angle and the injection pulse width according to the two, and the coolant temperature, the intake air temperature, and the like are condition parameters for correcting the basic ignition advance angle and the injection pulse width. The crankshaft (or camshaft) corner position signal is used to determine the ignition timing and injection timing relative to the top dead center of each cylinder. The throttle opening sensor signal is necessary for the idling condition judgment, the transition condition injection amount compensation, and the like. When a gasoline engine is equipped with a three-way catalytic converter, there must be an oxygen sensor installed in front of the catalytic converter (also installed one before and after the catalytic converter) that can reflect the air-fuel ratio for partial load and thermal idle conditions. The air-fuel ratio closed-loop control input feedback signal. The detonation intensity and frequency detected by the knock sensor are used as the basis for the electric controller to decide to delay ignition to avoid deflagration. Depending on the specifics of the engine, other sensors (such as boost pressure, oil pressure, vehicle speed and battery voltage, etc.) may be available.